Multidimensional online map of the disaster index of China's natural disasters. Legend is diversity ratio, in terms of severity, the ratio from strong to weak is 0.20-0.30; 0.17-0.20; 0.15-0.17; 0.13-0.15; 0.11-0.13;0.09-0.11; 0.07-0.09; 0.05-0.07 and 0.01-0.05.